The present invention relates to a method of shaping a plurality of tread patterns for motor vehicles, which bring about driving characteristics which differ from one another and which have tread blocks and/or tread ribs separated from one another by broad cut-outs and a plurality of find cuts in the tread blocks and/or ribs and also to vehicle tires shaped in accordance therewith.
The driving characteristics of motor vehicle tires are substantially determined by the kind, number and arrangement of the tread blocks and tread ribs which are formed by the introduction of broad cut-outs into the tread surface. The most diverse embodiments of motor vehicle tires with such tread blocks and tread ribs are known, which are selected in accordance with the desired driving characteristic, i.e. in accordance with the main intended purpose.
Moreover, it is known to provide fine lamella-like cuts or sipes in the tread blocks and tread ribs in order to further influence the driving characteristics of the tire. For example, in winter tires, such lamella cuts are used to improve the traction of the tire on snow. The external appearance of the tire is admittedly also influenced by these lamella cuts. This impression is, however, mainly determined by the tread blocks and tread ribs. This means that vehicle tires with different driving characteristics also have a considerably different appearance and this is a disadvantage in that tuning a tire""s pattern for a given performance causes an inevitable changes in its appearance.
The invention is now based on the object of setting forth a method of shaping tread patterns for vehicle tires with which tread patterns with different driving characteristics can be shaped, which nevertheless have essentially a corresponding same outer appearance.
Accordingly the object is satisfied in that a basic pattern of tread blocks and/or tread ribs is specified which determines the basic characteristics of the tire tread and which is the same for all tread patterns characterized by a pattern of fine surface cuts is additionally specified, which is substantially the same for all tread patterns, with the surface cuts being in each case basically introduced into the tread blocks and/or tread ribs of the tire with a low depth which does not substantially influence the driving characteristics of the tire, and in that, depending on the desired driving characteristic of the relevant tread pattern, sections of the fine cuts of this pattern are selected which are to be formed at least with a greater depth which co-determined the driving characteristics of the tire.
By the designing of all tread patterns with a corresponding basic pattern of tread blocks and/or tread ribs and with a corresponding pattern comprising a plurality of fine surface cuts, all the tread patterns have a corresponding outer appearance through the method of the invention. The surface cuts have essentially no influence on the driving characteristics of the vehicle tire, but rather serve solely for the optical design. However in order to be able to provide variation in driving characteristics of the tread patterns to give different performance characteristics, the fine surface cuts are formed section-wise with a greater depth, so that these sections co-determine the driving characteristics of the tire. The deepening section-wise does not, however, change the outer appearance of the vehicle in practice so that a change of the driving characteristics is possible without changing the outer appearance. Thus with the method of the invention, vehicle tires with different driving characteristics can be provided, which nevertheless have a common appearance.
In accordance with one embodiment of the invention, the fine cuts in the non-deepened sections have a depth of about 1 mm. In this way an influence on the driving characteristics is, on the one hand, precluded, and, on the other hand, a common optical appearance of the tires is provided.
In accordance with a further design of the invention the deepened suctions are also broadened somewhat in comparison to the fine surface cuts.
A first further development lies in the fact that the fine cuts at least partly have interruptions. In this way the appearance of the tire can be varied. Moreover, the basic characteristics of the vehicle tire are less strongly influenced than with uninterrupted cuts.
In accordance with a further embodiment of the present invention, the fine cuts end at least partly at a distance from the edges of the tread blocks and/or tread ribs. The optical appearance can also be varied further in this way. Moreover, the basic characteristics of the tire, which are pre-set by the tread block and the tread ribs, are also less strongly changed here.
A particular optical effect also results from the fact that, hn accordance with a further design of the invention, an encircling line formed as a fine cut is provided in at least some of the tread blocks and/or ribs at a small distance from the edge of the respective tread block or of the respective tread rib. The remaining fine cuts of the respective tread block or of the respective tread are in this arrangement in particular only provided within the region enclosed by the encircling line.
In accordance with a further embodiment of the invention, no fine cuts are present in selected regions of the tread pattern. The tread blocks or ribs in respective tread rib are in this arrangement in particular only provided within the region enclosed by the encircling line.
In accordance with a further embodiment of the invention, no fine cuts are present in selected regions of the tread pattern. The tread blocks or ribs in the shoulder region of the tire can in particular be formed without fine cuts. In this way the influencing of the basic characteristics of the tire by the pattern of fine cuts is also kept low. In addition, a further possibility of varying the optical appearance results.
The design of tread patterns with different driving characteristics can be additionally brought about by variation of the depths and of the widths and also of the lengths of said sections of the fine cuts. These sections can also be distinguished from one another and indeed both in one tire and also from tire to tire. The outer appearance of the tire is also advantageously not changed hereby.
In accordance with one embodiment of the invention, the fine cuts are arranged in a rhombus pattern. In this respect different rhombus angles are possible. In the same way one pattern of the fine cuts can be provided of non-crossing, preferably wave-shaped lines. Both variants result in large freedom in the determining of the desired running characteristics of the tire.
In accordance with a further embodiment of the invention, the fine cuts are arranged in a differently designed pattern over the width of the tire and/or over the circumference of the tire. In this way further possibilities of varying the running characteristics of the tire result. In particular the spacing and/or the angle of the lines of the pattern of find cuts can be selected differently relative to one another over the width of the tire and/or over the circumference of the tire.
In accordance with a further design of the invention, the lines of the pattern comprises fine cuts with an angle of inclination to the circumferential direction of the tire of ca. 30xc2x0 to ca. 60xc2x0, in particular ca. 40xc2x0 to ca. 50xc2x0. These angles of inclination have proved to be particularly advantageous in order to influence the running characteristics of the tire by section-wise deepening of the fine cuts.
In accordance with a further embodiment of the invention, the lines of the pattern of fine cuts have a spacing of ca. 5 to ca. 20 mm, in particular ca. 8 to ca. 12 mm. This has also proved advantageous for setting the desired running characteristics of the tire by section-wise deepening of the cuts.
According to another aspect of the invention a vehicle tire manufactured in accordance with the method of the invention has a tread pattern which includes tread blocks and/or tread ribs separated by broad cut-out grooves by which the basics characteristics of the tire are determined, characterized by a plurality of fine cuts in the tread blocks and/or in the tread ribs which are only introduced into the tread surface with a reduced depth, such that they do not substantially affect the driving characteristics of the tire. The fine cuts can in this arrangement have different depths and/or widths and also lengths, so that the vehicle tires of the invention can have respectively differing running characteristics with the same outer appearance. For one and the same vehicle tire the depth of the deepened sections of the fine cuts, their width and their length can at least be partly different.